Embossed locking tabs for cardboard cartons



April 23, 1963 F. E. FOBIANO EMBOSSED LOCKING TABS FOR CARDBOARD CARTONS Filed Nov. 13, 1961 2 Sheets-Sheet 1 INVENTOR. WA m j BY M m//m April 23, 1963 F. E. FOBIANO EMBOSSED LOCKING TABS FOR CARDBOARD CARTONS Filed Nov. 15, 1961 2 Sheets-Sheet 2 INVENTOR.

BY M Bfibhfihl Patented Apr. 23, 1963 3,086,691 EMBOSSED LOCKING TABS FQR CARDBOARD CARTQNS Frank E. Fobiano, Cincinnati, {)hio, assignor to Premier Qarton Company, Cincinnati, Ohio, a corporation of Ohio Filed Nov. 13, 1961, Ser. No. 151,632 3 Claims. (Cl. 229-35) This invention relates to cardboard cartons and more particularly the invention relates to cardboard cartons having locking corner tabs by which the corners between carton side panels are formed.

Cartons of the type to which the present invention is directed are formed by the manufacturer as one piece blanks and shipped as stacks of fiat blanks to the packager. The packager, either manually or through the use of automatic machinery, sets the cartons up and fills them with the merchandise which is ultimately to be sold to the consumer.

The manufacturer must give attention to the problems of the two different stages in which the carton is processed, namely, the stage of manufacturing the one piece blank and the later stage of setting up the one piece blank into the form of a box. At the manufacturer, the one piece blank must be formable in existing machinery in order to be economically feasible. Thereafter the packager must be able to form a box from the one piece blank as conveniently and economic-ally as possible. Obviously a carton design which effects economy in the operation of the packager is an attractive product and highly salable to the packager. The present invention is directed principally to the problems of the packager and it has been an objective of the invention to facilitate the formation of cartons from the blanks received from the manufacturer.

In the formation of a generally rectangular cardboard carton having a bottom panel, two side panels and two end panels, the end panels must be joined to the side panels in order to form a reasonably secure corner which will maintain the merchandise within the carton. The carton may have a covering panel, dividers and other extraneous features as required for the particular merchandise to be packaged. The corner lock of the present invention is adapted for use with all such different types of cartons, the only consideration being that corner joints must be formed between adjoining end panels and side panels.

In the formation of a corner joint, two fundamentally different approaches may be taken. In one approach, tabs formed either on the side panels or end panels may e joined by gluing to the adjoining panel thus forming a corner. The disadvantages of gluing should be fairly obvious. The other approach is to configurate a tab so that it can cooperate with the adjoining panel in such a manner as to lock the adjoining panels together. While such locking tabs have been successful, they do require a certain amount of manipulation, either manually or by automatic machinery in order to bring the cooperating locking surfaces into proper relationship or orientation with respect to each other so that a locking engagement is attained.

It has been an objective of the present invention to minimize the manipulation required of the cooperating locking surfaces in order to effect the locking at the corners of a carton.

It has been another objective of the invention to provide a tab lock configuration in which the locking surfaces snap into the proper orientation as the panels to which the tabs are mounted are brought into proper upright position.

'It has been a further objective of the invention to form a three-dimensional locking tab by forming an embossment on the tab, which embossment in passing into a cooperative relationship with the adjoining panel snaps in the tabs locking surface into proper engagement with the locking surface of the adjoining panel.

These and other objectives of the invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a carton employing the present invention,

FIG. 2 is a plan view of the one piece blank from which the carton is formed,

FIGS. 3, 4 and 5 are fragmentary side elevational views showing the steps of carton formation,

FIG. 6 is a plan view taken along lines 6-6 of FIG. 5, and

FIG. 7 is a cross sectional view taken along lines 7--7 of FIG. 5.

In the illustrated form of the invention a carton indicated at 10 is shown as being a simple tray or boat structure. It should be understood that the invention is applicable to other types of cartons wherein corner joints are formed between adjoining panels.

The principal elements of the carton are the bottom panel 11, the side panels 12 and the end panels 13.

Each end panel is formed with a locking tab 14 at each end thereof, each of the locking tabs having a projecting tongue 15, one edge 16 of which being normally inclined to the plane of the bottom panel and providing a locking surface.

The side panels 12, at each end thereof are formed with angulated slits 17, the slits providing an edge 18, normally inclined to the plane of the bottom panel which forms a locking surface to cooperate with the locking surface 16.

In the forming dies, a one piece blank shown in FIG. 2 is cut, slitted as at 17 and creased to provide fold lines 19 for the side panels, fold lines 20 for the end panels and fold lines 21 for the locking tabs 14. Diagonal reinforcing ribs 23 may also be formed.

Simultaneously with the cutting and scoring to form the blank, the tongues 15 are embossed to form indentations 25. The indentations take the form of protuberances on the outside surfaces of the tongues 15, the protuberances projecting beyond the plane of the locking tab a distance equal to approximately one-fourth of the thickness of the cardboard from which the blank is formed.

The manner in which the locking tabs with their tongues 15 are introduced into the slits 17 in the side panels is illustrated in FIGS. 3, 4 and 5. The tabs 14 as well as the side panels 12 are first bent at right angles to the plane of the one piece blank. Thereafter the end panels 13 are folded upwardly through a right angle to form the corners. As the end panels are folded upwardly, the slit 17 is opened slightly by forcing the V-shaped portion 26, formed by the slit, away from the plane of the side panel. The slit is opened only a sufiicient distance to permit the tongue 15 to pass through the slit.

The forward edge of tongue 15 which first enters slit 17 is V-shaped to facilitate its introduction into the slit. As the tongue passes through the slit from the position of FIG. 3 to the position of FIG. 4, the protuberance 25 bears against the inside surface of the side panel 12 and thereby forces the locking edge surface 16 away from the plane of the inside surface of side panel 12. In being forced away, the locking surface 16 is moved into registry with the locking surface 18 formed by the slit 17. Thus as the end panel swings in a counterclockwise direction, as viewed in FIGS. 3, 4 and 5, the locking surface 16 moves into engagement with the locking surface 18 and prevents the inadvertent withdrawal of the tongue from the slit 17.

FIGS. 6 and 7 illustrate the manner in which the locking surface 16 is forced outwardly by the protuberance 25 to underly the surface 18 of slit 17.

While a specific embodiment of the invention has been described with reference to FIGS. 1 to 7, it should be borne in mind that departures may be made from the preferred embodiment without departing from the scope and spirit of the invention which, in essence, resides in the embossing of locking tabs to provide assurance that the locking tabs will move into locking engagement with the surfaces with which they cooperate.

I claim:

1. 'In a rectangular carton constructed from a one piece blank comprising a bottom panel, each edge of said bottom panel having upstanding therefrom a side panel, a corner construction between adjoining side panels comprising a locking tab at the end of a first side panel, said side panel having a locking tongue extending outwardly therefrom, said locking tongue being embossed to provide an indented middle portion and having an upper edge forming a locking surface, the adjoining side panel having a slit adjacent the end thereof, the locking tab of said first side panel being folded around the end of said adjoining side panel and the locking tongue being inserted through said slit whereby the indented middle portion of said tongue engages an inside surface of the said adjoining side panel and spaces said locking surface away from said surface of said adjoining side panel whereby said locking surface is engageable with an edge of the slit.

2. A rectangular carton constructed from a one piece blank comprising a bottom panel, each edge of said bottom panel having upstanding therefrom a side panel, two of said side panels being located on opposite sides of said carton and having locking tabs at each end thereof extending laterally outwardly therefrom, each of said locking tabs having a locking tongue extending outward- 4 1y therefrom, each of said locking tongues being embossed to provide an indented middle portion and a lock surface at the edge thereof, the two other opposite side panel sections having angulated slits adjacent the ends thereof, the locking tabs of said first two side panels being folded around the ends of said two other opposite side panels and the locking tongues being inserted through said angulated slits whereby the indented middle portion of said tongues engages an inside wall of the said other side panels and spaces said lock surface away from the surface of said other side panels whereby the lock surface is engageable with an edge of the slit.

3. A rectangular carton constructed from a one piece blank comprising a bottom panel, each edge of said bottom panel having upstanding therefrom a side panel, two of said side panels being located Onopposite sides of said carton and having locking tabs at each end thereof extending laterally outwardly therefrom, each of said locking tabs having a locking tongue extending outwardly therefrom, each of said locking tongues being embossed to provide an indented middle portion and having an edge inclined to the plane of said bottom panel to form a lock. surface, the two other opposite side panel sections having angulated slits adjacent the ends thereof, each slit being formed at least in part by an edge generally parallel to said lock surface, the locking tabs of said first two side panels being folded around the ends of said two other opposite side panels and the locking tongues being inserted through said angulated slits whereby the indented middle portion of said tongues engages an inside wall of the said other panels and spaces said lock surface away from said surface of said other side panels whereby the lock surface is engageable with an edge of the slit.

References Cited in the file of this patent UNITED STATES PATENTS 1,652,251 Oliver et a1 Dec. 13, 1927 1,796,035 Maier Mar. 10, 1931 2,901,158 Carpino Aug. 25, 1959 

1. IN A RECTANGULAR CARTON CONSTRUCTED FROM A ONE PIECE BLANK COMPRISING A BOTTOM PANEL, EACH EDGE OF SAID BOTTOM PANEL HAVING UPSTANDING THEREFROM A SIDE PANEL, A CORNER CONSTRUCTION BETWEEN ADJOINING SIDE PANELS COMPRISING A LOCKING TAB AT THE END OF A FIRST SIDE PANEL, SAID SIDE PANEL HAVING A LOCKING TONGUE EXTENDING OUTWARDLY THEREFROM, SAID LOCKING TONGUE BEING EMBOSSED TO PROVIDE AN INDENTED MIDDLE PORTION AND HAVING AN UPPER EDGE FORMING A LOCKING SURFACE, THE ADJOINING SIDE PANEL HAVING A SLIT ADJACENT THE END THEREOF, THE LOCKING TAB OF SAID FIRST SIDE PANEL BEING FOLDED AROUND THE END OF SAID ADJOINING SIDE PANEL AND THE LOCKING TONGUE BEING INSERTED THROUGH SAID SLIT WHEREBY THE INDENTED MIDDLE PORTION OF SAID TONGUE ENGAGES AN INSIDE SURFACE OF THE SAID ADJOINING SIDE PANEL AND SPACES SAID LOCKING SURFACE AWAY FROM SAID SURFACE OF SAID ADJOINING SIDE PANEL WHEREBY SAID LOCKING SURFACE IS ENGAGEABLE WITH AN EDGE OF THE SLIT. 